Hiya
In response to Landing craft / boats:
I am more than happy to create the icons for you - great source material, Thanks! Plan veiws always great

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A few thoughts - You realise all the craft you suggested are HUGE, even the ELB is twice the length of the LCM-6 on which all the USMC monitors, etc were built. Either they will be enormous, unweildy icons or will need to be at a different scale / out of scale to fit (as the various LST are already in game).
Regarding upgrading and your worry that they will be antiquated - I am not sure this is true, as I understand it the current Landing craft of the British and US militaries are not that much different from those they used in WWII. (slightly improved anti-HEAT armour and speed). If you wanted a "Modern" version just make it slightly faster, increase the HEAT armour and update the weapons.
Where there has been an improvement is in the development of air cushion craft (Hovercraft). Perhaps some form of LCAC? Budget reforms have, unfortunatley, stopped production of new Finnish, British, American and Russian designs, but without finacial restraints all would have new hovercraft - both as Landing vehicles and (at least in the Finn case) armed missile craft.
I will get some prototype icons of the MFP, ELB, AF, AL amd PiLb sorted and posted within the next couple of days.